The one concept everything else builds on.
Understand what the 21 million limit actually is, and what it is not.
Almost every explanation of Bitcoin starts in the wrong place. It starts with price, or with "digital gold," or with a chart. None of that explains the thing that makes Bitcoin different from a number in a spreadsheet.
The thing that makes it different is that the supply is fixed by a rule, and the rule is enforced by everyone running the software rather than by an institution that can change its mind.
There will only ever be 21,000,000 bitcoin. Not approximately. The number is written into the software, and every participant in the network independently checks that nobody is creating coins outside the rules. A participant who tries is simply ignored by everyone else.
New bitcoin are not printed by a company. They appear as a reward. Roughly every ten minutes, the network confirms a batch of transactions — a "block." The participant who does the work receives a fixed number of new bitcoin, called the block subsidy, plus transaction fees. That subsidy is the only way new bitcoin enter existence.
Every 210,000 blocks — roughly every four years — the subsidy halves. This produces the 21 million cap.
| Halving | Date | Subsidy |
|---|---|---|
| 1st | 28 Nov 2012 | 50 → 25 BTC |
| 2nd | 9 Jul 2016 | 25 → 12.5 BTC |
| 3rd | 11 May 2020 | 12.5 → 6.25 BTC |
| 4th | 19–20 Apr 2024 | 6.25 → 3.125 BTC |
| 5th | est. ~Apr 2028 | 3.125 → 1.5625 BTC |
A fixed supply does not mean the price goes up. It means the supply cannot be inflated by any single party making a decision. That is the property. What you do with that property is the rest of the course.
Most people ask: "Should I buy Bitcoin?" That is not the right first question. The right first question is: "Do I understand what I am buying, and why it works the way it does?"
By Day 7, you will have the answer.
The full course covers DCA automation, custody, tax basics, and a 30-day system for running Bitcoin on autopilot — no trading, no charts, no stress.
This lesson is education. It is not financial, investment or tax advice, and it is not a personal recommendation to buy, sell or hold anything.
We are not authorised or regulated by the Central Bank of Ireland and we do not give advice tailored to your situation. Bitcoin is volatile — you can lose everything you put in. Any figures or historical prices are illustrative only.
You are responsible for your own decisions. For advice about your own circumstances, speak to a regulated financial adviser.